What is the purpose of the pulmonary system?

The purpose of the pulmonary system is foundational to the process of respiration. It is responsible for carrying blood to and from the lungs, allowing for the critical exchange of gases. In this system, deoxygenated blood is transported from the heart to the lungs, where it receives oxygen and releases carbon dioxide. After this gas exchange occurs, the oxygenated blood is then transported back to the heart to be pumped out to the rest of the body.

This function is essential for maintaining oxygen levels in the body and ensuring that carbon dioxide, a waste product of metabolism, is expelled. Other systems mentioned in the incorrect options serve different roles; for instance, while the circulatory system does carry oxygenated blood to the body, it is not the primary function of the pulmonary system itself. Similarly, filtering toxins and hormone production are functions attributed to the kidneys and endocrine system, respectively, and are not related to the primary purpose of the pulmonary system.